Poisson 单的叠加、随机选择与分解

讨论了两个独立Ｐｏｉｓｓｏｎ单的叠加、Ｐｏｉｓｓｏｎ单的随机选择和Ｐｏｉｓｓｏｎ单的分解,得到了Ｐｏｉｓｓｏｎ单的分解定理．     

Mn/B复合添加对铝硅合金富铁相特征的影响

在含1.0?的铝硅合金中复合加入一定量的Mn和不同量的B,采用OM、SEM、EDS及DSC等手段研究了B含量对铸态组织、富铁相比例及形貌的影响,并探讨了复合添加Mn/B的影响机制。结果表明：适量的B对Al-Si合金晶粒度、富铁相都具有明显的细化作用;添加3%Al-3B时,富铁相面积分数和平均颗粒尺寸分别从6.73%和11.2μm降至4.13%和7.5μm;在3%之内添加Al-3B可抑制粗大初生铁相的形成,促进富铁相由粗大星状初生铁相、大尺寸树枝状、网状共生富铁相向小尺寸致密度高的树枝状、汉字状和粒状富铁相状变;过量的Al-3B易导致多边形初生铁相的出现,但合金组织和共生铁相得到进一步的细化。     

Evidence for η6 Coordination to a Fullerene

Abstract

Evidence for the first η⁶ derivative of a fullerene, [MoC₆₀F₁₈(CO)₃] has been obtained from reaction between [Mo(CH₃CN)₃(CO)₃] and C₆₀F₁₈.     

Finding the optimal tradeoff between area and delay in multiple constant multiplications

Over the years many efficient algorithms for the multiplierless design of multiple constant multiplications (MCMs) have been introduced. These algorithms primarily focus on finding the fewest number of addition/subtraction operations that generate the MCM. Although the complexity of an MCM design is decreased by reducing the number of operations, their solutions may not lead to an MCM design with optimal area at gate-level since they do not consider the implementation costs of the operations in hardware. This article introduces two approximate algorithms that aim to optimize the area of the MCM operation by taking into account the gate-level implementation of each addition and subtraction operation which realizes a constant multiplication. To find the optimal tradeoff between area and delay, the proposed algorithms are further extended to find an MCM design with optimal area under a delay constraint. Experimental results clearly indicate that the solutions of the proposed algorithms lead to significantly better MCM designs at gate-level when compared to those obtained by the solutions of algorithms designed for the optimization of the number of operations.     

钒对T122铁素体耐热钢组织和性能的影响

研究了(%):0.11C- 11.89～12. 19Cr- 1.86～1.90W-0.37～0.38Mo-0.9Cu铁素体耐热钢T122 中 0.14%～0.31%V-0.05%Nb复合强化添加剂中V 含量对钢的组织和性能的影响。结果发现,随V 含量增加, 钢中δ铁素体量增加,室温拉伸强度、650℃拉伸强度和650℃持久强度逐渐降低;当V 含量为0.19%时T122 钢的室温拉伸强度、650℃拉伸强度和持久性能较高。 V 含量变化影响钢中M₂C、MX 和Laves相的析出, 0.19%V-0.05%Nb析出强化效果最好     

加成型硅橡胶在磁控管中的应用

本文介绍了加成型硅橡胶在磁控管生产中的应用和硅橡胶使用中的工艺细节对磁控管工作可靠性的影响,也说明了加成型硅橡胶的使用对于磁控管生产的积极作用。     

声波测井中几个重要问题的探讨

声波测井传输网络考虑了声源与接收器的电-声、声-电传输特性对测井信号的影响,使得测井信号能够更准确地反演所测量的地层。利用阵列测井仪可大大提高测井声信号的首波幅度,利用特殊的数字信号处理算法可将淹没在强噪声背景中的弱测井信号的首波信号提取出来。在提高首波幅度的同时,进一步考虑了实际声波测井仪中使用的薄圆管压换能器的指向性对测井信号的影响,提出了优化设计薄圆管压换能器的方法。     

Development of durable copper catalyst for hydrogen production by high temperature methanol steam reforming

Highly durable catalyst for high temperature methanol steam reforming is required for a compact hydrogen processor. Deactivation of a coprecipitated Cu/ZnO/ZrO₂ catalyst modified with In₂O₃ is very gradual even in the high temperature methanol steam reforming mainly at 500 °C, but the initial activity is considerably low. Addition of Y₂O₃ to Cu/ZnO/ZrO₂/In₂O₃ increases its initial activity due to the higher Cu surface amount, while the activity comes gradually close to that for the catalyst without Y₂O₃ during the reaction. Coprecipitation of Cu/ZnO/ZrO₂/Y₂O₃/In₂O₃ on a zirconia support triply increases the overall activity by keeping the durability while the amount of the coprecipitated portion is a half of that without the support. On the composite catalyst, sintering of Cu particles is suppressed. The surface Cu amount is similar to that without the support, but the Cu surface activity is much higher probably because of the small Cu particle size.     

广义递推T矩阵算法及其应用

递推Ｔ矩阵算法是一种计算散射问题的新型方法。本文对广义递推Ｔ矩阵算法的计算公式作了简单的推导并得到了其表达式。还论述了该方法与系列算法中其它方法之间的联系及优越性，并对波函数的加法定理进行了推广，证实了该定理同样适用于虚宗量的情况，将两方面的内容加以结合，应用于损耗介质散射场的计算。同时还计算了原文献中尚未涉及的媒质问题。最后，给出了二维条件下，该方法ＣＰＵ的计算时间与未知数的关系的图示。     

保健食品安全风险点研究

目的掌握市售保健食品的安全风险点,为监管提供技术支撑。方法对2014-2015年国家和省、市相关部门市场抽样的保健食品按照产品质量标准检验,对易非法添加的5类保健食品和假冒保健食品按照国家相关补充检验方法对非法添加物质进行检测,对可能存在食品安全的因素进行风险监测、检验与评估。结果1041批保健食品中不合格61批,合格率为94.1%。在不合格的保健食品中,功效成分/标志性成分不合格频次为36.1%,是保健食品不合格的首要因素。总黄酮、总皂苷、粗多糖、氨基酸总量和蛋白质不合格机率较高;理化指标不合格是保健食品不合格的第二大原因,不合格频次为24.6%,其中水分、灰分、铅等参数不合格的情况较常见,非法添加的不合格率为21.3%;假冒保健食品非法添加形势严峻,在101批额外检品中,检出非法添加83批,非法添加率高达82.2%,主要添加西地那非、西布曲明等。结论湖南省保健食品抽检合格率较高,风险点主要为非法添加和保健食品原材料控制不严,标准研究能力有待提升,对假冒保健食品和非法添加的打击力度有待进一步加强,法规有待进一步完善。